It is well known that several digital images can be edited on the same page of an editing medium. However, such a procedure requires prior preparation in front of a workstation in order to arrange the images one by one on the editing medium, for example by selecting the images and determining the zone in which it is wished to arrange these images. When it is wished to automatically edit several images an editing template is used for filling of the page of the editing medium. This template has zones which are practically identical to each other, intended to receive an image very often in even numbers. When the editing template is chosen, a template is selected which has a number of zones equal to the number of images to be edited or a little greater.
This type of editing is well suited to images of identical sizes such as series of digital images produced by equipment of the MRI or scanner type. It is necessary to know in principle the number of images to be edited on a single page of the editing medium.
In digital radiography, photoluminescent memory plates are used having different sizes, for example 18 cm.times.24 cm, 24 cm.times.30 cm, 35 cm.times.35 cm, or 35 cm.times.43 cm. These plates can also be exposed in both possible orientations, as can be seen in FIG. 1A. The larger dimension can be disposed vertically 11, hereinafter referred to as portrait format or arrangement, or the larger dimension can be disposed horizontally 12, hereinafter referred to as landscape format or arrangement. In addition, the image matrices are not necessarily proportional to the cassette sizes, for example a 24 cm.times.30 cm cassette and a 35 cm.times.43 cm cassette can have the same matrix of 2000.times.2500 pixels.
Traditionally, in radiography, the size of the cassette used to produce the image was chosen as a function of the dimension of the part whose image it is wished to obtain. The size of the image was very rapidly assimilated to the size of the medium which was used to record the image. When an editing of two images of an identical object is effected, each image being on a different page of an editing medium, the dimension of the matrix gives rise to an editing in which the objects represented have identical sizes on each editing medium whatever the cassette used. This is because the size of the object depicted or image edited depends on the pixel matrix and not on the physical size of the medium on which the image has been captured, that is to say the size of the cassette.
However, when several images are edited in a conventional fashion on a single page of an editing medium comprising several editing zones of identical dimensions, the existing software packages adapt the external dimensions of the image, for a radiograph of the size of the cassette, to the dimensions of the editing zone. The ratios of enlargements of various edited images or depicted objects can therefore be different when the cassettes do not have the same size or the same orientation.
As can be seen in FIG. 1A, when the images of two identical objects obtained by means of two identical cassettes are edited on a single page of an editing medium, one arranged in portrait format and the other arranged in landscape format, the conventional editing of the images on two editing zones of identical sizes 13 and 14 modifies the enlargement of the images in order to adapt them as well as possible to each editing zone. In the present case the enlargement is determined by the ratio of the greatest size of the image to the width of the zone 13 for the image 12, and to the width of the other zone 14 for the image 11. The result gives rise to two images of different sizes, as depicted.
As can be seen in FIG. 1B, when the images of two identical objects obtained by means of two different cassettes 21 and 22 are edited on a single page of an editing medium having two identical editing zones 23 and 24, the adaptation of the images obtained in the usual fashion to editing zones of identical sizes gives rise to images with different enlargements.
When an editing template is chosen, it may turn out that the number of images to be edited does not correspond to any available template. In this case, the user chooses a template having more editing areas than images to be edited and certain zones will be left empty. This happens for example when the available templates have an even number of editing zones and it is wished to edit an odd number of images.
In some applications, and in particular in radiography, the reader must be able to evaluate the dimensions of one organ or another on several views. It is therefore important, at final editing, to preserve, between these images, the enlargement ratios existing between the original images.
When it is desired to preserve the existing enlargement ratio between the original images, it is necessary to apply, to all the images, an enlargement coefficient calculated by means of the ratio between the dimension of the largest image and the dimension of the zones receiving the image, zones which are identical. When several images are edited on a single page with preservation of the enlargement ratio between these images, the same enlargement coefficient is applied to all the images. In these circumstances the images formed on radiographic plates of small size do not fill all the surface of the editing zone and the surface of the editing medium is not optimally used.